RSA Decryption Exercise

Two prime numbers p and q are chosen, and n $=$ pq is computed as follows:

p $=5,$ q $=11=>$ n $=511=55.$

The product n must be greater than $36$ to enable encryption of all characters and numbers.

Calculate $\backslash$phi No $=($p$-1)($q$-1)=(5-1)(11-1)=410=40.$

To create public key choose e $=3(1<$ e $<\backslash$phi No$,$ and e and $\backslash$phi No are co$-$primes$).$

The public key is: $($e$,$n$)=(3,55).$

To calculate private key, solve: $($ed$)$ mod $\backslash$phi No $=1.$

The private key is: $($d$,$n$)=(27,55).$

Encrypted message

The message was encrypted converted to numbers using the table below, and then encrypted using public key $(3,55).$

The encrypted message is $"390149205201"$

Decrypted message

The message is decrypted using the private key $(27,55).$

The first letter of the encrypted message is decrypted:

S $=$ Cd mod n $=$ mod$(3927,55)=19,$ which is letter S in number format.

What is the original $($decrypted$)$ message, when the encrypted string is $"390149205201"?$